On Sat, 26 Jun 2021 19:11:25 +0100 Brian <a...@cityscape.co.uk> wrote:
> > A choice between analogue and digital? You really were well off. We > had to train carrier pigeons to peck out a message with their beaks > and we needed to be adept at semaphore. Drum skills were a must. > There is no 'digital', it's all analogue with a poor signal/noise ratio. And no, I'm not kidding. Some of the more obscure digital faults turn out to require actually looking at the data with a (real) oscilloscope, where its analogue nature can usually be seen very clearly. Reflections, jitter, eye height, these are all analogue issues. I once fixed a fault where a particular simple logic IC had to come from a particular manufacturer, and someone had fitted one of the same type number but from a different manufacturer, that had a different input impedance. Real bleeding-edge, state-of-the-art hardware, that was. -- Joe
